A handsome production assistant for the Comedy Central show “Tosh.0” was shot and killed by cops in LA who mistook him for a stabbing suspect on Monday.

Aspiring producer John Winkler, 30, had rushed to an apartment in West Hollywood — after hearing screams — to help two friends, who were being held at knifepoint by alleged attacker Alexander McDonald, 27, according to the LA Times.

McDonald slashed Winkler, leaving him covered in blood, so he and a friend ran outside to escape. When LA County sheriff’s deputies got to the scene at around 9:30 p.m., they spotted Winkler outside the home — wearing a black T-shirt, just like the suspect, the paper reported.

It looked like Winkler was lunging toward his pal, so cops fired a shot, killing him with a single bullet, according to police. Another bullet struck his pal in the leg.

Cops realized they had opened fire on the wrong guy after they ran inside and discovered McDonald choking one of the other victims on the floor, police said.

Officers broke up the fight and arrested McDonald, who was charged with torture, murder and attempted murder. His bail was later set at $4 million, the news network KTLA reported.

“It’s just a really sad story,” said Winkler’s roommate Devin Richardson. “He basically went to help some neighbors and ends up getting shot.”